DESCHUTES BASIN — The Central Oregon Irrigation District is in the final planning stages of a $360 million project to replace a main canal with pressurized pipes. The project targets a section leading to more than a thousand landowners between Bend and Redmond, Oregon.

The district delivers most of its water through open canals constructed 120 years ago and blasted from porous lava rock. Nearly half the water in these canals evaporates or seeps into the ground before reaching its destination. The piping project is tied to commitments for water conservation during drought conditions and protections for endangered species.

The Central Oregon Irrigation District holds rights to use more than half of the Deschutes River's volume. During the last drought, state water law required commercial farmers downstream to fallow their land while the district diverted four times the amount of water its landowners' crops consumed. State legislators said district landowners are doing exactly what the law encourages them to do.

To keep water rights, districts must prove to the state that their customers are consistently using water "beneficially." More than 9 out of 10 acres in the district were pasture, which is considered beneficial use under the law. "What should we do? I think we should leave more water in the river. Legally speaking, that doesn't have to happen," said state Rep. Ken Helm.

In exchange for federal and state funding for the piping initiative, the district has pledged to send water downstream to farmers outside the district. Evan Thomas, a farmer and leader of the North Unit irrigation district, stated that the pipe must be installed by 2028. "This pipe has to go in the ground by 2028 or North Unit, all of Jefferson County, basically quits farming," Thomas said on March 1, 2024. The North Unit irrigation district serves a valley known for commercial farms and has rights to far less water from the Deschutes River than the Central Oregon Irrigation District does.

A threatened species of frog lives where irrigation districts have long siphoned water from the Deschutes River. Irrigation districts agreed to leave more water in the river over time to stave off lawsuits under the Endangered Species Act. Oregon and other Western states have rejected legislation that restricts what people can grow or how efficient they must be.